Final answer:
A real-time operating system (RTOS) and a microprocessor enable the execution of concurrent tasks. (option a)
Step-by-step explanation:
A real-time operating system (RTOS) enables the execution of concurrent tasks. An RTOS is designed to handle real-time systems where tasks have strict timing requirements. It allows multiple tasks to run simultaneously and provides mechanisms for task synchronization and communication.
A microprocessor is a general-purpose computing device that can also execute concurrent tasks. It has multiple cores or supports multithreading to enable parallel execution of tasks.
However, unlike an RTOS, a microprocessor doesn't provide real-time guarantees.
On the other hand:
Digital set-top boxes are devices primarily used for receiving and decoding digital television signals.
Networking units generally refer to devices used in computer networks for communication and data exchange.
Microprocessors are central processing units that form the core of a computer system but do not inherently provide real-time capabilities.
The correct choice for enabling the execution of concurrent tasks is a Real-time operating system (RTOS), as it is explicitly designed to handle tasks with strict timing requirements, ensuring timely and predictable execution.